Apparatus for filling



5, 1944. R. J. STEWART Erm.' 2,364,400

APPARATUS FORFILLING Filed June g1, 1940 Patented Dec. 5, 1944lAPPARATUS FOR FILLING Robert J. Stewart and Henry H. Franz, altimore,Md., assignors to Crown Cork & Seal Company, Baltimore, Md., acorporation of New York Application June 21, 1940, Serial No. 341,744

14 Claims.

This invention relates to apparatus for lling, and more particularly, tomechanisms for filling milk containers. The present application is acontinuation in part of our application for Filling structure, SerialNo. 215,680, filed June 24, 1938.

In machines heretofore used for lling milk containers, it has been thepractice to provide a rotary reservoir having downwardly extendingfilling nozzles or heads. The bottles or other containers to be lled areconveyed to and positioned on suitable platforms below these fillingheads and, as the reservoir revolves, each bottle is raised until itsmouth engages a depending filling head. 'I'he engagement between thebottle and head is operative to open a valve structure usually builtinto the lling head, and the opening of the valve permits gravity iiowof milk from the reservoir into the bottle. The air -which wouldotherwise be trap ed in the bottle and prevent the free flow of milk isvented through an unobstructed vent tube generally extending verticallyand centrally through the filling head with the upper end of the tubeextending above the milk in the reservoir. Thus the air in the bottle isforced by the in-owing milk to pass through the vent and into the top ofthe reservoir which is at atmosphericV pressure.

It will be appreciated that with such a construction, usually termed agravity filler, the speed with which a bottle may be filled is limitedby reason of the fact that the iii-flowing milk must push the airtrapped in the bottle upwardly through the vent. I

Another necessary element of this gravity lling equipment is theprovision of a displacement member on the lower end portion of the airvent tube which is positioned within the neck of thebottle. Thisdisplacement member must be provided because during the lling cycle, themilk will flow into the bottle until it is lled and will then continueto flow upwardly in the air vent tube until the latter is lled to thesame level as the surrounding liquid in thereservoir or tank. When thebottle has reached the end of the filling cycle and is moved downwardlyfrom the filling head, thus permitting the filling valve to close, themilk in the open vent tube will ow downwardly into the bottle. Thevolume displaced by the displacement member in the bottle is just equalto the volume of liquid that has flowed into the vent. Therefore, whenthe bottle on the platform has been lowered away from the filling headuntil the displacement member has been wholly withdrawn from its neck,the liquid owing from the vent tube into the bottle neck will completelynu it to the desired level.

In other words, the volume of the displacement member must be equal tothe capacity of the vent tube, plus the volumeof the air space to bepurposely left in the mouth of the bottle,

above the milk, after the bottle has been filled to the desired level.If every bottle is to be filled accurately to the same level, the levelof the liq uid in the reservoir must be controlled to a fine degree,because if the level varies to any extent, the volume of liquid thatwill ow into the vent tube in the filling process will vary, and as thedisplacement member always provides the same volume in the bottle thatmust be filled, any difference in volume of liquid which flows back outof the vent tube will be apparent in the level to which the bottle isfinally filled. Therefore, with this displacement type of gravityfilling head, an extremely accurate control of the liquid level in thereservoir must be maintained.

The limitation of the size of the displacement member and the diameterof the bore of the vent tube, in addition to requiring a fine adjustmentof the level of the liquid in the reservoir, also restrict the quantityof liquidA that may be contained in the reservoir. The diameter of thevent tube bore must be large enough to permit a free flow of airtherethrough. It is evident that the volume of liquid which will flowinto the bore lduring the filling process is directly related to thediameter of the bore and the level to which the liquid will flow intothe vent tube is governed by the level of liquid maintained in thereservoir. With the type of apparatus above described it has beennecessary to maintain this level relatively low in order that a toolarge volume of liquid will not flow into the vent and thus require anunduly large displacement member.

It will be observed that by the above arrangement time is consumed infilling the space previously occupied by the displacementmember andthere is'nothing to prevent the unsanitary dripping of milk from thefilling heads.

In addition to the gravity flow milk filling machines discussed above,another type in general use includes a vacuum tank above the bottleplatform and provided with iilling heads which are connected both to thevacuum tank and to a milk tank positioned at a point below the bottleplatform, with a flow line angled to a point above the filling headsextending between the milk tank and the filling heads. By thisarrangement, the positioning of a bottle in contact with a filling headcauses a vacuum circuit to be closed between the vacuum tank and themilk tank so that milk will be drawn upwardly from the latter throughthe angled passage and into the bottle. When the bottle is moveddownwardly, the vacuum line to the milk tank will be broken. This willcause the milk in the outlet portion of the angled flow line to flowdownwardly into the bottle to fill the space previously filled by the Iusual filling head diplacement member, while milk and foam already inthefilling head vent tube will be drawn upwardly into the vacuum tank.

The above method also has the disadvantage of requiring time to have thespace occupied by the displacement member filled with milk during thefinal portion of the filling cycle. Also, there will be dripping of milkfrom the angled passage after a bottle is removed therefrom.

Other arrangements used to fill milk involve the use of an extremelyhigh vacuum of the order of approximately fifteen inches of mercury, theprincipal idea of such. arrangements being to keep the milk isolatedfrom air. The difficulty with such an arrangement is that unless themilk is to be prevented from increasing its bulk, due to the exertion ofsuch a high vacuum upon its natural air content, a plurality of tanksmust be provided, thereby greatly complicating the filling apparatus.Also, milk under such a high vacuum is in a rather unstable conditionand readily tends to foam, particularly when it is sucked or drawn intoa bottle and thereby impacts with a bottle surface. The use of such ahigh vacuum also causes difiiculty in releasing the bottles from thefilling heads. In fact, a vacuum of only three or four inches of mercurywill cause bottles to adhere to the filling heads.

In addition to the above disadvantages of the prior machines and theirmethods, there is another problem peculiar to the filling of milk whichthey have entirely failed to overcome. That is, when milk is owed into abottle from a point above the bottle, it foams to a substantial extentand some time is required to displace this foam with solid milk. Theprior machines and methods have approached this problem by flowing themilk as rapidly as possible with the idea that the more rapid the flowof the milk the more quickly the bottle will be filled with solid milk.This theory, while entirely logical, cornpletely overlooks the fact thatthe rapid flow of the milk, resulting in a sharpened impact with thebottle, induces a greater amount of foaming than would be the case ifthe milk is flowed at somewhat reduced velocity.

We have discovered that if the filling is so performed that the milkwill flow into the bottle in an ample stream but at reduced velocity,less foaming will occur, and since less foam must therefore be removedbefore filling is completed, the time required for filling will bemarkedly reduced.

For example, the usual milk filler requires eight or nine seconds tofill a quart bottle with solid milk by following the prior system offlowing the milk as rapidly as possible into the bottle with norestriction on velocity. We have found that by fiowing the milk in astream of the same cross-sectional area as previously used, but withless velocity, less foam is produced. As a result little or not time isrequired to remove foam, and the same bottle can be filled with solidmilk in approximately six seconds.

The principal object of the present invention is the provision of amethod and apparatus for rapidly filling milk containers in an entirelysanitary manner.

The method whereby the above object is obtained may be generallydescribed as establishing within the milk reservoir and the containerY avacuum having a measurement just slightly greater than the head of themilk in the reservoir. For example, if the milk has a head of twelveinches at the filling heads, a vacuum equal to eighteen inches of milkwill be entirely sumcient; in fact, less vacuum is usually ample. Themilk is then flowed from the reservoir into the container in a stream ofthe usual volume but with the stream impeded by a bame or a tortuouspath so that it will flow with a velocity somewhat lower than that withwhich it would ordinarily flow under the same head with unrestrictedpassages.

A vacuum of twelve inches of milk corresponds to a vacuum of only oneinch of mercury.

The present method, involving the use of a vacuum effect in the milkreservoir above the bottles, entirely prevents all dripping of milk orleakage from the reservoir at any point. In other words, at any pointwhere dripping or leakage might occur, air is tending to enter thereservoir and milk obviously cannot-l escape. Furthermore, the use ofsuch an arrangementwith an extremely low vacuum effect enablescontinuously open vent tubes of small bore to be used. thereby reducingthe size of the vacuum pump required.

The ability to use vent tubes of small diameter is also due to the factthat the only function of the vent tubes is to draw surplus milk andfoam up into the reservoir immediately the bottle is moved out ofcontact with the filling head. That is, in milk fillers of the gravitytype discussed above, the milk which flowed into the vent tube was usedto fill the space previously occupied in the bottle by the displacementmember, and it was desirable to have the vent tube of large dlameter inorder to enable this replacing flow to occur as quickly as possible.Since the vent tubes of our `invention do not have this function, theymay be of smaller bore. Furthermore, the use of small vent tubes reducesthe air velocity of air in the filling tank and decreases thepossibility of milk being atomized and drawn to the vacuum pump.

The use of a vacuum in the milk reservoir to quickly draw surplus milkand foam up into the milk reservoir, for which only a very low vacuum isrequired, is to be distinguished from the prior use of a vacuum in atank above the filling head for the purpose of lifting milk from areservoir below the bottle. That4 is, in the prior construction, thedegree of vacuum was gauged according to the distance which the milk hadto be lifted from the reservoir below the bottle, whereas by ourinvention, the vacuum is merely for the purpose of quickly liftingsurplus milk back into the reservoir above the bottle. It is also to benoted that the use of the vacuum effect in the present method has nopurpose whatever in controlling the rate of filling a container, but issimply used to maintain a fixed head of milk, whereas the priorarrangements discussed immediately above which use the vacuum to liftthe milk from a point below the bottle determine the rate of filling bythe rate of vacuum. In other words, in such prior fillers the rate ofvacuum was increased in order to more quickly lift the milk from a pointbelow the bottle.

It has also previously been proposed to use milk filling machinesincluding a milk reservoir above the bottles, with a vacuum conditionwithin the reservoir. Also, the filling heads of these machines havebeen provided with vent tubes. However. these vent tubes were providedwith valves adapted to be closed as soon as a bottle moved downwardlyfrom the filling head. These prior arrangements, therefore, cannotfunction to immediately draw surplus milk through the vent tube up intothe filling reservoir when the bottles move from the filling head due tothe fact that the vent tube is then immediately closed. Because of this,any surplus milk moving up into the Vent tube simply remains there untila second bottle is placed under the filling head. The

usual practice is to have the vent tubes extending vertically toward thetop wall of the filling tank with the result that milk moving from thevent tube is directed against such top wall, resulting in foaming andatomization, some of the atomized particles being drawn into the vacuumpump. By the present invention, each vent tube has its upper portioninclined toward the side of the filling tank at such an angle as toprevent splash and thereby atomization and also to reduce foamproduction in the filling reservoir.

The features of the present invention whereby foaming is reduced permitsa filling tank of smaller size to be used. Prior milk filling machineshave been provided with relatively large filling tanks, for example,with the usual fourteen head filling machine a filling tank ofthirty-three gallons displacement is provided in order to accommodatethe large volume of foam returned from the bottles and produced in thefilling tank by the contact of the returned stream upon the top Wall ofthe filling tank. By the use of our invention 4it is found that afllling tankof only twenty-seven gallons capacity need be provided witha fourteen head machine.

It is also to be noted that the reduction of foam Within the fillingtank is highly desirable from the standpoint of sanitation, since foamwithin the filling tank represents a tremendous amount of air-exposedsurface which results in aerating and thereby contaminating thepasteurized milk.

Another object of the present invention is to provide a milk fillingapparatus of extreme simplicity and which includes a minimum number ofparts.

It is to be noted that in milk handling equipment, simplicity is theultimate design consideration, because less time is consumed in theoperation of cleaning and sterilizing equipment that has few parts andis of simple construction. As'v sterilization may be performed severaltimes in one day and, as every part of the dairy equipment that comes incontact with the milk must be so cleansed, the time required forcleaning has a marked bearing upon the cost of handling milk.

A still further object of the invention is to provideha readilyremovable deformable valve element of the type disclosed in the patentto Robert J. Stewart, for Filling apparatus, No. 2,127,892, issuedAugust 23, 1938, and to further improve upon the structure disclosed inthat patent.

Other objects and advantages will be apparent from the followingspecification and drawing, wherein- Figure 1 is a vertical sectionthrough the filling tank and a filling head and shows a bottle on itsplatform about to engage and open the filling valve, and

Figure 2 is an enlarged vertical section through a filling head showingthe neck of a bottle in 3 filling position with the valve of the fillinghead in fully opened position.

The filling machine here disclosed has a liquid supply reservoir I0mounted for rotary movement in any well known manner.' A cover II isprovided which has a substantially air-tight engagement with the edgesof the aperture I2 in the upper wall of the reservoir. Cover II`includesan apertured boss I3 which rotates with the cover II within a fitting I4connected to a vacuum line I5 whereby a low pressure condition isestablished Within the upper portion of the reservoir I0 above thesurface of the milk therein. Milk is delivered to the reservoir IUthrough any suitable pipe system including a tube I6 supported withinthe central and upper portion of the boss I3 and having a fioat valve I1connected at its lower end so that flow of milk into the reservoir willbe controlled by float I1 to maintain the reservoir filled to apredetermined point as indicated in Figure 1.

The reservoir III is provided with a series of circumferentially spaceddepressions or pockets I8 including bottom walls I8a and inclinedsurfaces I8b. Each pocket has welded therein a collar or shell I9forming a part of a filling head. Each pocket I8 andthe associated shellI9 thereby form a tube.

Each shell I9 is of generally cylindrical form and is provided with astraight bore 2I which-is bevelled at its upper edge as indicated at 22,The wall of each shell is reduced in thickness at its lower end asindicated at 23 to provide a downwardly facing shoulder 24. Asubstantially fiat washer 25 of known .type and formed of thin metalcontacts with the shoulder 24 and extends outwardly to receive allotherwise drip into a bottle. A deformable valve element 26 ispositioned upon the reduced portion 23 with its upper surface in contactwith the collar 25. Valve element 26 is formed of resilient materialsuch as rubber and includes a relatively thick walled neck portion 21which surrounds the reduced portion 23 of shell I9 and contacts with thecollar 25. Each valve element also includes a depending and inwardlyextending thin walled bulbiform lower portion 28 which normally has itslower edge 3I seated upon a conical seat 32 formed at the lower end ofthe vent tube 33 as described in said Stewart Patent No. 2,127,892.

At the upper end of the bore through the neck portion 21, there isprovided an annular ridge 3ft. By this arrangement, the bore of the neckportion does not have contact with the portion 23 of shell I9 over itsentire area, but only at the extreme lower portion of the -bore and atthe ridge 34. The upper surface of the neck portion 2'I is also providedwith an upwardly facing shoulder 35 at a point spaced from the borethrough the neck portion. This shoulder bears upon the under surface ofthe collar 25.

The provision of the ridges 34 and 35 on valve element 26 urges thelower edge of its neck bore toward firm engagement .with the surface 23so that no milk can fiow between the valve element and surface 23 whenthe valve is flexed as shown in Figure 2.

Vent tube 33 is fitted within the bore 2I of shell I9, being centeredwithin the shell by means of ribs 36 which are outwardly extended attheir upper ends to provide inclined shoulders 31 to bear upon thebevelled surface 22 at the upper inner edge of shell I9.

` As is described in the said patent of Robert J. Stewart, thedeformable valve element 26 will nor-l condensation which might mally beheld seated upon the valve seat portion 32 of the corresponding venttube 33, but when a bottle is raised to have its lip contact with thelower portion of the valve element as shown in Figure 2, this portionwill be lifted from seat 32 so that milk may ilow downwardly into thebottle in an annular stream.

Each vent tube 33 is of relatively small diameter and has acorrespondingly small bore 38 so as to reduce the cross sectional volumeof the milk which may be drawn up into it. The lower end of the bore 38is tapered as indicated at 39, this tapered portion extending into arestricted portion I of bore 33. Restriction 43 is preferably providedfor the purpose of reducing the size of the aperture through which airmay ilow when no bottle is beneath the head and also to further preventdripping of milk from the vent tube.

A ange or washer Il is provided upon the tube 33 at such point that theunder wall of the ange or washer will be spaced from the upper surfaceof the bottom wall I3a of the pocket I8 by a distance which would be notless than one-sixteenth of an inch so as not to be clogged by butterfatparticles in buttermilk, the rate of flow being controlled by thespacing at this point The outer edge of the ilange element is preferablyrounded in vertical cross section. The upper rounded edge of the flangedeiines the inner wall of a converging annular mouth leading to theannular passage C--A-B between the other portions of the flange andopposed Walls of the pocket I8. It will be observed that the ribs 36terminate at a point adjacent the downwardly inclined portion of theilange 4 I By the above arrangement, the flange 4I comprises a baille orobstruction in the path of downwardly moving milk and, with the opposedwalls I3a and I8b of the pocket I8, forms a tortuous passage for themilk. Movement of the milk through this passage naturally decreases itsvelocity by friction and turbulence. By having the restriction at thepoint A with a larger space below the same as at point B, turbulence isincreased. It will therefore be observed that though the tortuouspassage thus provided will deliver to the space B between the outer wallof the vent tube and the inner wall of the bore of shell I3 a supply ofmilk to till the capacity of that space,

such milk will move into the space at a reduced velocity, so that itwill. drop with less force into the bottle. The portion of the tortuouspassage between the under-surface of the bottom wall Isa of pocket Illforms a horizontal course in the tortuous passage. This horizontalcourse, which naturally causes the stream to deviate from the vertical,increases turbulence in the stream.

As soon as the lip of a bottle is sealed against the portion 28, the aircontained in the bottle will be drawn upwardly through the constantlyopen vent tube by reason of the low pressure area maintained above theliquid in the reservoir. As the bottle moves further and opens thevalve, the liquid above the valve will ilow through the passage providedbetween the shell I! and the vent tube 33 under the influence ofgravity. However, because of the fact that the milk must move throughthe tortuous passage C-A-B, its velocity will be decreased so that themilk will not flow downwardly at a speed entirely commensurate with itshead. The liquid moving down through the filling head will strike theconical seat 32 of the vent tube and will be deflected toward the wallot the bottle. This will prevent the mouth oi the vent tube 33 frombeing obstructed during the nlling process.

It will be noted that each pocket la and the associated shell Is form anouter tube element, while vent tube 33 forms an inner tube element, theopposed surfaces of the two tube elements deilnlng an annular passage.

When the bottle has been completely iilled, milk will flow up into thevent tube to the level of the body of liquid in the lling tank. Thepressure acting on the surface of the liquid in the illling tank andthat on the surface of the liquid in the vent tube being equal, the flowcondition of liquid will momentarily be balanced.

After the bottle is completely filled and the above described staticcondition is obtained, the bottle platform will lower the bottle awayfrom the filling head. Such static condition will be maintained untilthe bottle has been lowered so far that the seal between the bulbiformportion of the valve and the lip of the bottle is broken, at whichmoment the valve will already have been closed to further flow. Breakingof the seal between the bottle lip and the valve will permit atmosphericpressure to enter the neck of the bottle. It is to be noted that thevacuum maintained in the filling tank is preferably only of sufiicientdegree to cause the milk in the vent tube to be drawn up into thereservoir or, in other words, pushed up into the reservoir by theatmospheric pressure acting through the lower end of the vent tube.

It will be noted that the upper portion l5 of vent tube 33 is inclinedoutwardly to lie at an obtuse angle to the side wall of reservoir I0.Because of this, milk projected from the upper end of tube 33 willstrike the side wall of the reservoir at an obtuse angle and will owquietly down the reservoir wall, thereby preventing splash andatomization, and assisting in holding foam to a minimum.

When the bottle has been completely lowered away from the valve, thevent tube will, of course, be open to atmosphere and maintained openuntil another bottle moves into illling position beneath that Yfillinghead. The restriction 40 in the vent tube'insures against the drippingfrom the vent tube of any liquid that might cling to the wall of thebore of the tube and also reduces the volume of the air stream which maypass through it.

It will be observed that the present method, eliminating the necessityof a. large displacement member at the bottom of the vent tube, providesfaster filling because it is not necessary for any liquid to movedownwardly through the vent tube to lill the space previously occupiedby a displacement member.

As a bottle moves downwardly from the position shown in Figure 2 topermit the valve 26 to close, milk will simultaneously ll the space inthe mouth of the bottle occupied by the lower end of the vent tube. Inthis manner, full lling of the bottle is assured.

As has been stated above, the degree of vacuum or low pressuremaintained through the line I5 is preferably relatively low, being onlysuiiicient to draw up into the filling tank the milk which flows up intothe vent tube. It is found that the vacuum will be ample if it is only50% higher than the head of the milk in the lling tank. For example, ifthe milk is maintained to a depth of twelve inches in the lling tank andthereby has a head of twelve inches at the nlling valve, a vacuum equalto eighteen inches of milk will beY entirely sumcient. In tact. in mostinstallavtortuous passage for flow of the milk through each filling headfurther reduces the velocity of iiow of the milk without restricting thesize of the ow passage. Provision of an extremely low vacuum has thefurther advantage of preventing the high percentage of air normally inmilk from being expanded. Such expansion tends to create foaming,particularly when the milk lcontacts with the bottle during filling orwhen it moves upwardly through the vent tube 33 into contact with thefilling tank wall.

It is found that by reducing the foaming of the milk as occurs with ourmethod, the necessity Aof a large filling tank is obviated. Most priorfilling machines are equipped with a relatively large filling tank,primarily to accommodate the foam which forms in the tank during thefilling process. Since the present method inhibits foaming toasubstantial degree, it is not necessary to provide as large a fillingtank. For example, prior machines provided with filling tanks includingfourteen filling heads are normally of a capacity of thirty-threegallons while by our method a fourteen head machine filling tank needonly be of twenty-seven gallons capacity. The reduction of foam withinthe filling tank obviousiy is a great advantage from the standpoint of'sanitation because foam tremendously increases the surface area exposedto air and contamination.

Because of the fact that the present method reduces foaming to aminimum, it is possible to fill a bottle much more rapidly with solidmilk. As has heretofore been stated, prior filling methods, using arapid flow of milk-into'the bottle, have resulted in foaming and asubstantial proportion of the filling time has been occupied inwithdrawing foam from the bottle and replacing the same with milk, thetime required for a quart bottle being from eight to nine seconds.Because the present method inhibits foaming, it insures that the bottlewill vlll rapidly with solid milk, a quart bottle usually requiringabout six seconds for filling. The ability to fill faster with solidmilk by the present method is due entirely to the fact that we fiow theusual volume of milk but at a lower velocity, this low velocity beingdue to the fact that the milk stream, while of normal cross' section,must move about a baille, 0r in a tortuous path.

It may be stated that because of the lowered velocity of the milkflowing into the bottle by the present method such small foam bubbles asmay form around the lower portion of the vent tube 33 and between theextreme lower end of the'vent tube and the mouth of the bottle can risequickly into the tank through the incoming stream of milk. Removal offoam has been extremely diflicult with prior methods and machinesbecause of the high velocity and head of the descending milk.

The bore of the vent tube which may be used with the present method isextremely small. Heretofore it has been necessary to provide a largevent tube of the order of nine-sixteenths of an inch in diameter toquickly draw foam into the filling tank from the bottle. Reducing thesize of the vent tube to approximately sevensixteenths of an inch at itssmallest portion, as may be done with the present method, particularlywith the vacuum system, has the material advantage of enabling thevacuum pump to be of small capacity. Also, the smaller the diameter ofthe vent tube, the smaller the quantity of milk which will be in thetube after the bottle is filled and the less possibility there is ofsuch milk foaming when it contacts with the filling reservoir wall. Venttubes of reduced size also reduce the air velocity in thel upper portionof the filling tank, thereby decreasing the tendency toward carryingatomized milk from the filling tank toward the vacuum pump.

bubbles from this area Since each vent tube is open to atmosphere duringthe short interval between the removal and delivery of bottles, it isdesirable to reduce fiow through the same as much as possible. The useof constantly open vent tubes in itself has numerous advantages overprior machines because such tubes eliminate valves and insure thatsurplus milk will be instantly drawn upwardly into the filling tank. Theuse of a low pressure condition'in the filling tank also has inherentadvantages serving to give faster and more accurate filling, as Well asprevent the filling of imperfect bottles.

It will be observed that the use of a very slight vacuum of the,degreedefined above permits the present machine to operate with only a sin-gietank for the milk, whereas machines operating under a higher vacuum mustbe provided with a series of reservoirs in order to avoid exerting toohigh a vacuum directly upon the surface of a body of milk. Our use of aconstantly open vent tube likewise eliminates the necessity of aplurality of tanks at different pressures, as well as eliminating aseries of valves as pointed out above.

The terminology used in the specification is for the purpose ofdescription and not of limitation, the scope of the invention beingindicated by the claims.

Furthermore, while the embodiment of the invention specificallydescribed herein refers to the filling of milk it will be observed thatat least a number of features of the invention are entirely applicableto the handling of other liquids.

We claim:

1. In a filling machine, a reservoir, means to maintain a body of liquidin the reservoir and an uninterrupted low pressure condition above thesurface of such liquid, a filling head communica'ting with the liquidcontaining portion of the reservoir, said filling head including a valveto control the flow of liquid from the reservoir, and a continuouslyopen vent tube adapted to communicate at its lower end with a containerpositioned beneath the filling head, the upper end of the .tube beingcontinually open to the upper portion of the reservoir, the bore of saidvent tube including a restriction to prevent dripping.

2. In a rotary filling machine, a reservoir having a centrally aperturedcover, means to maintaina body of liquid-in the reservoir including aliquid supply pipe, and means to maintain a low pressure condition abovethe surface of such liquid including a suction head concentric with saidpipe and disposed vertically through said lcentrally apertured coverinto said reservoir, a

lllng head communicating with the liquid containing portion of thereservoir, said iling head including a shell, a resilient valve adaptedto be carried by said shell to control the now of liquid from thereservoir, and an open vent tube adapted to communicate at its lower endwith a contalner positioned beneath the filling head, the upper end ofthe tube being continually open to the upper portion of the reservoir,the lower end of said vent tube being enlarged to provide a seat forsaid resilient valve and being also provided with bottle centeringmeans, and the bore of said vent tube being reduced adjacent itslowermost end.

3. In a illling machine, a lling reservoir including a bottom wall and avertically extending side wall, a illling head iny said bottom wallincluding an outlet flow valve, a vent tube in said filling head, saidvent tube extending upwardly through said iilling head and having atleast its upper portion inclined toward the side wall of said llngreservoir so as to project liquid moving from the tube against said sidewall at an obtuse angle with respect to said side wall.

4. In a milk lling machine, a milk reservoir, a iilling head includinga'valve to control downward flow of milk to a container positionedbeneath the filling head, the filling head including concentric innerand outer tubes positioned to define between them an annular milk :dowand foam return passage, said inner tube serving as a vent tube, one ofsaid tubes having a radially extending baffie thereon within saidpassage and spaced above its lower end and projecting into the annularpassage, the other of said tubes being so formed adjacent said baillethat, in vertical section, its annular passage surface willsubstantially conform to the vertical sectional outline of said bailleto define a tortuous path including a substantially horizontal coursewhich path will produce turbulence in and exert friction upon the milkto reduce its velocity and enable such foam as is created in thecontainer to readily rise through the descending milk stream.

5. In a milk filling machine, a milk reservoir, a filling head includinga valve to control downward flow of milk to a container positionedbeneath the iillng head, the illling head including concentric inner andouter tubes positioned to denne between them an annular milk flow andfoam return passage, said inner tube serving as a vent tube, and havinga radially projecting baille on its outer surface within said passage'and spaced above its lower end, the inner surface of said outer tubebeing enlarged in diameter adjacent and opposite said radiallyprojecting baille so that such portion of the inner surface of the outertube will substantially conform to but be spaced from said radial bailleto define a tortuous path including a substantially horizontal coursewhich will produce turbulence in and exert friction upon the milk toreduce its velocity and enable such foam as is created in the containerto readily rise through the descending milk stream.

6. In a milk iilling machine, a structure of the character described inclaim 4 wherein the space between said inner tube and said outer tube ismore restricted at one portion along said baille than at another portionalong said baille.

7. In a milk nlling machine, a structure of the character described inclaim 4, wherein the space between the lower surface of said radialbaille on said inner tube and the opposed conforming surface of saidouter tube is less than at other opposed portions of said tubes.

8. In a milk nlling machine, a structure of the character described inclaim 5 wherein the space between said inner tube and said outer tube ismore restricted at one portion along said baille than at another portionalong said baille.

9. In a milk filling machine. a structure of the character describedin'claim 5, wherein the space between the lower surface of said radialbaille on said inner tube and the opposed conforming surface of saidouter tube is less than at other opposed portions of said tubes.

10. In a milk filling machine, the combination with a structure of thecharacter described in claim 4, of means to maintain a vacuuml conditionin the milk reservoir suillcient to draw surplus milk upwardly throughsaid inner tube.

1l. In a milk filling machine, the combination with a structure of thecharacter described in claim 5, of means to maintain a vacuum conditionin the milk reservoir suicient to draw surplus milk upwardly throughsaid inner tube.

12. In a milk filling machine, a milk reservoir, a iilling headincluding a valve to control downward flow of milk to a containerpositioned beneath the illling head, the iilling head includingconcentric inner and outer tubes positioned to respectively define theinner and outer surfaces of an annular milk flow and foam returnpassage, said outer tube including a circular wall of relatively largediameter at its upper end, a substantially horizontal and annular wallat the lower end of said iirst-named wall portion, and a verticalcircular wall of reduced diameter extending downwardly from the inneredge of said annular horizontal wall, said inner tube having a radiallyprojecting flange positioned within said large-diametered circular wall,the lower surface of said flange being spaced above said horizontal walland its diameter being greater than the diameter of said verticalreduced-diameter circular wall so as to define a tortuous path adjacentsaid flange which will produce turbulence in and exert friction upon themilk to reduce its velocity and enable such foam as is created in thecontainer to readily rise through the descending milk stream.

13. In a milk filling machine, a structure of the character described inclaim 12 wherein the space between said inner tube and said outer tubeis more restricted at one portion along said ilange than at anotherportion along said flange.

14. In a milk filling machine, a structure of the character described inclaim 12 wherein the space between the lower surface of said iiange onthe inner tube and said horizontal surface of said outer tube is morerestricted than at other opposed portions of said tubes.

ROBERT J. STEWART. HENRY H. FRANZ.

